The study of 23,000 men and women who were followed for an average of 12 years found that "self-reported coffee consumption was inversely related to stroke risk," said study leader Yangmei Li, an epidemiologist at the University of Cambridge in England.

Li was to present the findings Thursday at American Stroke Association's annual stroke conference, in San Antonio.

Overall, people who reported any intake of coffee had a 27% lower risk of stroke than those who said they never drank java, the researchers reported. Drinking more coffee was not associated with a greater reduction in stroke risk.

And the reduced risk was "irrespective of the type of coffee consumed, caffeinated, decaffeinated, instant or ground," Li said.

Daniel Lackland, a professor of epidemiology at the Medical University of South Carolina and a spokesman for the American Stroke Association, said the new research isn't groundbreaking, but it does confirm previous findings.

"This is consistent with other studies that have looked at coffee drinking," Lackland said. But, he added, "nobody really knows the mechanism."

Studies have shown that coffee consumption is associated with a lower risk of developing type 2 diabetes -- a major risk factor for stroke -- and also with a reduced risk of heart disease, Lackland said. But those studies generally have not been carried out with rigorous methods, he said.

"Typically, they rely on self-reports, how much coffee you say you drink," Lackland said. "But what might be two cups for me might be an entirely different two cups for you."

So, there are no official suggestions that people drink coffee to lower their risk of stroke, Lackland said. "There has been no study designed to produce the kind of evidence needed to make recommendations," he said.